A Mouse Model of Acute Ethanol and Burkholderia Infection

Abstract

Abstract Alcohol consumption both, acute and chronic has well-documented effects on the immune system. Melioidosis is an infection caused by Burkholderia pseudomallei of public health importance in Southeast Asia and Northern Australia. Alcohol consumption has been described as risk factor associated with B. pseudomallei infections in humans. Evidence supports the importance of alcohol consumption as a risk factor for development of meliodosis, but few experimental studies have focused on ethanol effects on Burkholderia spp. infection. In these studies, we propose the use of the closely related B. thailandensis E264 as a useful BSL-1 model to study the effects of alcohol on host’s immune responses. Female C57BL/6 were administered ethanol (4 g/kg) intraperitoneally 30 min before intra-nasal infection with 1 × 105 B. thailandensis CFU. Animals were euthanized at 24 and 72 hr post-infection (PI), blood and tissues were collected to determine bacterial dissemination. Our results at 24 hr showed bacterial dissemination to the lung, liver, and spleen in the alcohol group. Spleen had the largest number of bacteria present. At 72 hr PI, bacteria were found only in the lungs and the brains of mice administered alcohol. Mice in the alcohol group had significantly larger spleens at both time points. Furthermore, serum and tissue cytokine concentrations (TNF-α, GM-CSF, IL-10) were decreased by alcohol. These results provide insight into the effects of a culturally prevalent meliodosis risk factor, acute alcohol consumption as a predisposing factor for melioidosis. Future work will determine mechanisms of alcohol on bacterial dissemination and how this translates to B. pseudomallei and melioidosis rates of infection.